FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * NBGE Manager, LLC   2. Issuer Name and Ticker or Trading Symbol Proto Labs Inc [PRLB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O NORTH BRIDGE GROWTH EQUITY, 950 WINTER STREET, SUITE 4600 3. Date of Earliest Transaction (Month/Day/Year) 08/22/2012 (Street) WALTHAM, MA 02454 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 08/22/2012   J(1)   1,600,000 D $ 0 4,821,790 I By North Bridge Growth Equity I, L.P. (2) Common Stock               1,126 D (3)   Common Stock               610 D (4)   Common Stock               585 I By Angel 2011 Dynasty Trust (5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
NBGE Manager, LLC C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454		X
NBGE GP, LLC C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454		X
NORTH BRIDGE GROWTH EQUITY I LP C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454		X
North Bridge Growth Management, L.P. C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454		X
ANDERSON EDWARD T C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454		X
DAMORE RICHARD A C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454		X

Signatures

/s/ Julie M. Regnier, Attorney-in-Fact for NBGE Manager, LLC		08/24/2012
**Signature of Reporting Person		Date
Julie M. Regnier, Attorney-in-Fact for NBGE GP, LLC		08/24/2012
**Signature of Reporting Person		Date
Julie M. Regnier, Attorney-in-Fact for North Bridge Growth Equity I, L.P.		08/24/2012
**Signature of Reporting Person		Date
Julie M. Regnier, Attorney-in-Fact for North Bridge Growth Management, L.P.		08/24/2012
**Signature of Reporting Person		Date
Julie M. Regnier, Attorney-in-Fact for Edward Anderson		08/24/2012
**Signature of Reporting Person		Date
Julie M. Regnier, Attorney-in-Fact for Richard D'Amore		08/24/2012
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The transaction reported on this Form 4 represents a pro rata distribution, and not a purchase or sale of securities, by North Bridge Growth Equity I, L.P. to its general and limited partners without consideration.
(2)	Represents shares held directly by North Bridge Growth Equity I, L.P. NBGE Manager, LLC ("NBGE") is the managing manager of NBGE GP, LLC, which is the sole general partner of North Bridge Growth Management, L.P., which is the sole general partner of North Bridge Growth Equity I, L.P. NBGE has sole vesting and dispositive power over such shares. Shared voting and investment power over such shares is vested in the managers of NBGE, Edward Anderson and Richard D'Amore. Mr. Anderson and Mr. D'Amore each disclaim any beneficial ownership of such shares, except to the extent of any pecuniary interest therein. This report shall not be deemed an admission that any of the reporting persons is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.
(3)	Represents shares held of record by Mr. Anderson received in connection with the pro rata distribution from North Bridge Growth Equity I, L.P. referenced in footnote 1 above.
(4)	Represents shares held of record by Mr. D'Amore received in connection with the pro rata distribution from North Bridge Growth Equity I, L.P. referenced in footnote 1 above.
(5)	Represents shares held of record by a trust for the benefit of certain of Mr. Anderson's immediate family members which were received in connection with the pro rata distribution from North Bridge Growth Equity I, L.P. referenced in footnote 1 above. Mr. Anderson's immediate family member is the trustee of the trust. Mr. Anderson disclaims beneficial ownership of these shares, and the filing of this report is not an admission that Mr. Anderson is the beneficial owner of these securities for purposes of Section 16 or any other purpose.

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